Vacuum cleaner



R. B. J. HULTBERG 1,959,759

VACUUM CLEANER Filed Dec. 22, 1932 2 Sheets-Sheet l May 22, 1934.

NvENToR B a ATroRNEY May 22, l934- R. B. J. HULTBERG 1,959,759

VACUUM CLEANER Filed Deo. 22, 1932 z'sheets-sheet 2 w ATroRNr-:Y

Patented May 22, 1934 UNITED STATES VACUUM CLEANER Rolf Bertil Johannes Hultberg, Stockholm,

Sweden, assignor to Electrolux Corporation, Dover, Del., a corporation of Delaware Application December 22, 1932, Serial No. 648,325 In Sweden May 7, 1932 11 Claims.

The invention relates to the vacuum cleaner art and particularly to apparatus for indicating when the dust bag of a cleaner requires emptying.

In a vacuum cleaner, a fan is usually employed to draw air through a cleaning tool. This air picks up dust from the object being cleaned, such as a carpet, and this dust is carried by the flow of air into a dust bag made of pervious material through which the air passes but which prevents the passage of dust and other objects drawn into the bag. The dust therefore collects in the dust bag and after continued use the dust thus collected interferes with the passage of air through the walls of the dust bag. This in turn reduces the ow or" air through the cleaning tool and hence reduces the efficiency of the device. Also, the air drawn into the vacuum cleaner is often employed to cool the electric motor used to operate the fan. Upon a reduction of the quantity of air passing through the cleaner, due to a dirty bag, the cooling elect is reduced and the motor may become overheated.

The main object of this invention is to provide an indicating means which will give warning when the resistance to the flow of air to the bag has reached such a value that the bag should be cleaned. 'I'his is not dependent alone on the quality of dust in the bag inasmuch as a small quantity of very line dust will clog the bag to the same extent as a larger quantity of less fine dust.

Another object of the invention is to provide an indicating means which will give warning when the cleaning tool, or the hose connecting the cleaning tool with the rest of the cleaner, becomes clogged, asby a piece of cloth or the like being caught therein.

Further objects and advantages of the invention will become apparent from the following description considered in connection with the accompanying drawings-which form a part of this specification and of which:

Fig. 1 is a side view of a vacuum cleaner, partially in cross-section, showing the preferred form of my invention;

Fig. 2 is an enlarged view, chiefly in cross-section, of the indicating device shown in Fig. 1;

Fig. 3 is a top view, partially in cross-section, of the device shown in Fig. 2; and

Fig. 4 is a cross-sectional view of a somewhat modied indicating device.

Referring more particularly to Fig. 1, reference character designates a cylindrical barrel made of sheet metal or other suitable impervious material. Secured to one end of barrel 10 is a ring 11 formed with an annular shoulder 12. A ring 13 having a portion 14 is adapted to t within and against the shoulder 12. The portion 14 is provided with a seal 15 made of rubber or the like which, when pressed against the shoulder 12 69 forms an air-tight seal. A dust bag 16 made of suitable cloth which is pervious with respect to air but prevents the passage therethrough of dust, and having a cylindrical form is secured to ring 13. The dust bag is provided with a circular bottom 17 to which is secured a piece of tape or the like 18 which serves as a handle when emptying the bag. A bell-shaped member 19 is adapted to engage ring 11 and is held in place by means of catches 20. The sealing member 15 70 is squeezed between the bell 19 and the shoulder 12 of ring 11. 'I'he central portion of bell 19 is provided with a threaded air inlet opening which is adapted to receive a threaded coupling member 21 which in turn is adapted to receive the cleaning hose 9 leading from a cleaning tool 8.

Within the other end of barrel 10 there is suitably mounted an electric motor 22 having a shaft 23 upon which is mounted the rotor or rotors of a centrifugal fan 24. The rotors 24 are enclosed within a fan housing 25 forming a fan chamber having a centrally located opening 26 shielded by a perforated plate 27. The motor end ofthe barrel is closed by means of a cylindrical member 28secured to the barrel 10 by means of catches 29. Member 28 isprovided with a. centrally located exhaust or outlet opening 30 which is threaded to `receive the coupling member 21. Barrel 10 and members 19 and 28 together comprise a casing which is substantially air-tight with the exception of the inlet and exhaust openings.

Secured to the top barrel 10 at the motor end thereof is a standard 31 which supports one end of a handle 32. The standard 31 also encloses an electric switch 33 for opening and closing 95 the motor circuit. The switch also carries contact members 34 which are adapted for engagement with an electric plug. The casing is supported on a pair of runners 53 so as to be easily slid'able over a supportingsurface.

The other end of handle 32 is supported in a -second standard 35. This second standard also encloses a dust indicating member, designated generally by reference character 36. An opening 37 in the top of standard 35, covered, if de- 105 ment with an opening formed in a plate 39a which is secured in air-tight relation to the outside of barrel 10. Sleeve 39 extends through an opening formed in the barrel 10. The upper end of the sleeve is provided with an outwardly extending flange 40 while the lower end is provided with an inwardly extending ange 41. An inverted cup-shaped diaphragm 42, made of elastic material such as rubber or the like, is provided with an annular flange around its lower edge which is forced against the flange 41 of member 39 by means of a Ilanged disc 43, which may be threaded on to sleeve 39. The center of disc 43 is provided with a threaded opening into which is screwed a hollow member 44. A anged member 45 is carried by member 44 and retains the lower end of a spring 46. The other end of spring 46 abuts against a plate 47 carried by the cylindrical portion'of diaphragm 42. A rivet or the like 48 secures the plate 47 to the diaphragm and is provided at its upper end with a partially spherical head.

A lever 49 is pivoted within standard 35. The more central portion of lever 49 rests upon the spherical portion of rivet 481 while the other end of the lever engages a rotatable visual signal 50. Signal 50 comprises a semi-cylindrical member rotatably mounted on bolts 51 (see Fig. 3) which are screwed through the sides of the standard 35. A spring 52 engages the semi-cylindrical member and one of the bolts 51 and is arranged to tend torotate the semi-cylindrical member in a clockwise direction, as viewed in Fig. 2. The free end of lever 49 bears against the semi-cylindrical member and, when this end of the lever is raised it rotates the semi-cylindrical member in a counter-clockwise direction, against the force of spring 52. One half of the semi-cylindrical member -is preferably colored white, while the other half is preferably red, so that upon rotation in a clockwise direction the white part will pass out of sight and the red part will appear below the opening 37.

'I'he operation of the device is substantially as follows:

Upon rotation of fan 24 by the motor 22 a current of air is caused to enter the dust bag 16 through the coupling 21 from the tool connected thereto by means of the hose 9 or the like. This air carries with it dust and dirt picked up by the cleaning tool and this dirt is deposited in the dust bag, the air passing through the walls thereof to the fan. The air discharged from the fan passes through or around the motor 22, thereby cooling the latter, and is discharged from the cleaner through the exhaust opening 30.

The dust bag at all times offers some resistance to the ow of air therethrough and hence the absolute pressure existing within the dust bag is somewhat higher than the absolute pressure existing within the barrel 10 immediately outside of the bag. As dust accumulates within the bag, the drop of pressure through the latter increases and hence the absolute pressure existing in the casing outside and adjacent the bag (that is, the suction pressure of the fan) becomes lower. This pressure is communicated to diaphragm 42 through the opening in member 44. Atmospheric pressure acts upon the outside of the diaphragm and tends to collapse it against the force exerted by spring 46 and, the pressure existing in the barrel l0. As the latter pressure falls, the atmospheric pressure is able to collapse the diaphragm, thereby causing member 48 to move downwardly, which in turn causes lever 49 to pivot in a counter-clockwise direction. The end of lever 49 therefore moves downwardly and allows spring 52 to rotate the semi-cylindrical signal 50 in a clockwise direction, thereby causing red to show in the opening 37. 'I'his indicates to the operator that sufcient dust has collected within the bag 17 to reduce the efficiency of the vacuum cleaner and that the bag should be removed and emptied.

If desired, the signal may have a diagonal thereon to show the extent of movement thereof and the area to one side of the diagonal line may be red and the area to the other side white. Alternatively a portion visible only at very low fan suction pressure may be red and a diagonal line may be placed across the remaining white portion.

To remove the bag it is only necessary to un fasten catches 20, whereupon bell 19 may be removed and the bag withdrawn from within the barrel 10 and emptied in any suitable place.

Likewise, if the cleaner tool or the hose connecting it with coupling 21 becomes clogged, it will result in a decrease in absolute pressure from the point of obstruction to the fan. In other words, an abnormally low pressure exists in both the dust bag and in the space 10 immediately surrounding the dust bag. 'I'his will cause the indicator 36 to show red. If the operator then cleans the dust bag and replaces it the indicator will continue to show red, whereupon hevknows that there is an obstruction in the cleaning tool or hose.

In the modification of the indicating device shown in Fig. 4, reference character 10 again indicates the barrel of the vacuum cleaner in which is located the dust bag 16. Secured to the upper side of barrel 10 is a standard 60, which is,located in substantially the same position as is standard 35 in Fig. 1. Standard 60 provides support for one end of handle 32. The left hand part, as shown, of the standard, is formed with a recess 61 having a window 62. The window may be covered by a piece of glass o1' other transparent material 63.

Secured within recess 61 is a cylindrical cupshaped member 64 having an opening 'through the bottom thereof. Suitably secured to the lower part of member 64 is a spring retaining member 65 provided with an annular ange 66. A diaphragm 67, which may be made of any suitable flexible material such as rubber or paper,.

is secured between the bottom of member 64 and the flange 66 of member 65. The central part of diaphragm 67 is provided on its upper side, as viewed in Fig. 4, with a washer 68 of rigid material and on its lower side with a cup 69 in which seats a spring 70. The other end of the spring abuts against the bottom of member 65. Washer 68 and cup 69 may be secured to the diaphragm by means of a rivet or the like 71 and these three elements constitute a rigid member` secured to the central part of the diaphragm.

Pivotally mounted within member 64 above diaphragm 67 is a signal 72. The pivot point 73 is preferably directly above rivet 71. The signal 72 has a flat portion 74 beneath the pivot point which is integral with a substantially vertical portion 75 upon which is secured a member 76 made of heavy material such as lead. Integral with the upper part of portion 75 is a portion 77, one half of which may be white, as at 78, while the other half may be colored distinctively, such as red, at 79. Member 65 is provided with an aperture which establishes communication between the under side of the diaphragm and the interior of barrel 10, while a passage 81 establishes communication between the upper side of the diaphragm through recess 61 to the atmosphere.

In operation, as dust and dirt accumulate in bag 16, the resistance to flow of air through the bagbecomes greater and the pressure within the casing immediately outside the bag is reduced, as has been explained in connection with the embodiment shown in Fig. 1. This reduction of' pressure is communicated through opening to the under side of the diaphragm 67. The diaphragm is urged upwardly by the pressure within the casing aided by the expansive force of spring 70, and against the pressure exerted by the atmosphere. As the pressure within the casing becomes less, the pressure of the atmosphere is able to move the diaphragm downwardly and rivet 71 moves away from the dat portion 74 of signal '72. The weight 76 now causes the signal to rotate about pivot 73 in a clockwise direction. This causes the red part '79 to appear underneath window 62, where its presence indicates to the operator that the dust bag requires cleaning or that the hose has become clogged.

When the machine is at rest and the pressure within the casing is atmospheric, there is no force to balance theexpansive force of spring '70 and hence it forces the diaphragm upwardly until washer 68 strikes two or more projections on member 64, thus preventing further movement of the diaphragm. In-this position, which is the one shown in Fig. 4, the signal is held so that the white portion thereof is visible through window 62. When the bag is-clean, the pressure in the casing is not reduced sufciently by the fan to cause the signal to be rotated in a clockwise direction, as above described. However, as the pores of the bag become clogged, the pressure is reduced in the casing and the indicator gives warning that the bag should be cleaned in order that the cleaner may operate eiliciently.

While there have been shown and described Atwo more or less specific embodimentsof the invention, it is to be understood that many variations thereof fall within its scope, which is to be determined by the appended claims considered in the light of the prior art.

What is claimed is:

1. A vacuum cleaner comprising, in combination', an air-tight casing, a dust bag in said casing, a motor in said casing, a fan in said casing driven by -said`motor, a hollow member on said casing, asignal mounted in said hollow member and means enclosed by said hollow member and said casing responsive to diilcrential pressure between the atmosphere and the interior of said casing between the dust bag and the fan for moving said signal.

2. The combination with a vacuum cleaner comprising an air-tight casing, a clust separating member in said casing and means for producing flow of air through said casing and said member, of apparatus for indicating the conditionof said dust separating member comprising a diaphragm supported by said casing and having one side in communication with the atmosphere and the other side in communication with the interior of said casing on the suction side of the dust separating member, a spring tending to move said diaphragm against the pressure of the atmosphere, and a signal movable in response to movement of said diaphragm.

3. The combination with a vacuum cleaner comprising an air-tight casing, a dust separating member in said casing and means for producing flow of air through said casing and said member, 0f apparatus for indicating the' condition of said dust separating member comprising a diaphragm supported by said casing and having one side in communication with the atmosphere and the other side in communication with the interior of said casing on the suction side of the dust separating member, a spring tending to move said diaphragm against the pressure of the atmosphere, an arm pivoted with respect to said casing and arranged to be rotated by movement of said diaphragm, and a signal rotatable by movement of said arm.

4. The combination with a vacuum cleaner comprising an air-tight casing, a dust separating member in said casing and means for producing flow of air through said casing and said member, of apparatus for indicating the condition of said dust separating member comprising a diaphragm supported by said casing and having one side in communication with the atmosphere and the other side in communication with the interior of said casing, a spring tending to move `said diaphragm against the pressure of the atmosphere, a signal pivoted above said diaphragm, said signal having a flat portion adapted to be contacted by said diaphragm to be moved thereby and a circular portion constituting a visible signal, said signal being so weighted withrespect to the pivot point that said dat portion rests against said diaphragm.

5. A vacuum cleaner comprising an air-tight casing, a dust bag in said casing, a motor in said casing, a fan in said casing driven by said motor, a hollow-member on said casing, a cup-shapedk member retained in said hollow member, a member secured to said cup-shaped member, a diaphragm held between said two last-mentioned members, one side of said diaphragm being in communication with the interior of the casing on the suction side of the dust bag and the other side with the atmosphere, and a signal pivoted within said hollow member and arranged to be rotated by movement of said diaphragm.

6. A vacuum cleaner comprising an air-tight casing, a dust bag in said casing, a motor in said casing, a fan in said casing driven by said motor, a hollow member on said casing, a cup-shaped member retained in said hollow member, a spring retaining member secured to said cup-shaped member, a diaphragm held betweensaid two lastmentioned members, one side of said diaphragm being in communication with the interior of the casing on the suction side of the dust bag and the other side with the atmosphere, a spring be-` tween said spring retaining member and said diaphragm, and a signal pivotedwithin said hollow member and arranged to be rotated by movement of said diaphragm.

'7. A vacuum cleaner comprising an air-tight casing, a dust bag in said casing, a motor in said casing, a fan in said casing driven by said motor, a hollow member on said casing, a signal comprising an arcuate surface rotatably mountedin said hollow member, a diaphragm carried by said casing, one side of said diaphragm being in communication with the interior of said casing on the suction side of the dust bag and the other side with the atmosphere, and a member pivoted within lsaid hollow member and arranged to transmit motion from said diaphragm to said arcuate surface. l

8. In apparatus of the character set forth, an air-tight casing, a hollow member mounted on said casing, a windowv formed in said hollow member,v a signal movably mounted within said hollow member so as to be visible through said window, a cup-shaped membersecured within said hollow member, a third member secured to said cup-shaped member, a diaphragm held between said cup-shaped member and said third member and having one side in communication with the-atmosphere and the other side with the interior of said casing, and means for transmitting movement of said diaphragm to said signal.

9. In apparatus of the character set forth, an air-tight casing, a hollow member mounted on said casing, a window formed in said hollow member, a cup-shapedmember secured within said hollow member, a signal pivotally mounted in said cup-shaped member so as to be visible through said window, a third member secured to said cup-shaped member, a diaphragm held between said cup-shaped member and said third member and having one side in communication with the atmosphere and the other side with the interior of said casing, and means for transmitting movement of said diaphragm to said signal.

10. In apparatus of the character set forth, an air-tight casing, a hollow member mounted on said casing, a window formed in hollow member, a cup-shaped member secured Within said hollow member, a signal pivotally mounted in said cupshaped member, said signal comprising a member having a substantially horizontal portion, a substantially Vertical portion and a curved portion, said curved portion being distinctively marked and being visible through said window, a weight secured to said vertical portion, a spring retaining member secured to said cup-shaped member, a diaphragm held between said cupshaped member and said spring retaining member, a spring between said spring retaining member and-said diaphragm, one side of said diaphragm being in communication with the atmosphere and the other side with the interior of -said casing, said signal being so mounted with respect to said diaphragm that the horizontal portion of said signal is adapted to be contacted and moved by upward movement of said diaphragm. f

11. In apparatus of the character set forth, an air-tight casing, a hollow member mounted on said casing, a window formed in said hollow member, a cup-shaped member secured within said hollow member, a signal pivotally mounted in said cup-shaped-member, said signal comprising a member having a substantially horizontal portion, a substantially vertical portion and a curved portion, said curved portion being distinctively marked and being visible through said window, a`weight secured to said vertical portion, a spring retaining member secured to said cupshaped member, a exible diaphragm held between said cup-shaped member and said spring retaining member, a rigid member` secured to the central part of said diaphragm, a spring between said spring retaining member and said` rigid member, said cup-shaped member forming a.l

stop for said rigid member, one side of said diaphragm being in communication with the atmosphere and the other side with the interior of said casing, said signal being so mounted with respect to said diaphragm that the horizontal portion of. said signal is adapted to be contacted by said rigid member and moved by upward movement of said diaphragm.

ROLF BERTIL JOHANNES HU'LTBERG. 

